(a) Field of the Invention
The invention concerns a trailer of the type in which the width can vary depending on specific needs. More particularly, the invention is directed to a trailer that is provided with a mechanism which enables to move apart the carrying wheels, while obtaining a loading box that can be expanded in the same proportions.
(b) Description of the Prior Art
The use of trailers hitched behind a vehicle often results in problems of width, specially with respect to small trailers that one would wish to place behind a small vehicle such as an all-terrain vehicle. Under these circumstances, one must turn to trailers of different widths, alternatively resort to a trailer that can be adjusted to different widths.
Structures that permit the expansion and the retraction of a trailer are known such as those described in the following US patents:
U.S. Pat. No. 4,221,398
U.S. Pat. No. 4,772,038
U.S. Pat. No. 5,249,823
U.S. Pat. No. 5,326,128
U.S. Pat. No. 5,332,276
However, these structures are all as much complicated as one another and do not permit the construction of a retractable and expandable trailer at a reasonable cost that is also easy to operate.
It is an object of the invention to provide a trailer whose width can be modified if needed, that is not costly and is easy to adjust.
The present invention concerns a retractable and expandable trailer comprising a rectangular framework, a loading box fixed to the framework and including a horizontal freely rotatable carrying wheels enabling to pull the trailer. The latter is characterized in that there are provided two frames disposed under the framework and arranged to engaged into one another between an expanded position of the trailer where the frames are drawn apart from one another and a retracted position of the trailer where the frames are drawn nearer to one another, supports fixedly mounted on the framework, the framework holding the frames by means of the supports, the supports being arranged to permit a simultaneous transverse and longitudinal movement of the frames with respect to the framework when the frames are moved from an expanded position to a retracted position, the eanying wheels being respectively fixed to the two frames, and an articulation device permitting to move the frames by transverse and longitudinal sliding in the supports from an expanded position to a retracted position and vice versa, Longitudinal members adapted to juxtaposed the horizontal platform on both sides thereof in expanded position of the trailer.
Preferably, the trailer comprises a front panel rising from the front end of the rectangular framework, to join the vertical lateral panels and thereby constitute the loading box.
The rectangular framework preferably includes lateral sides; a rear side and a front side and a central link, fixed between the rear and front sides; the longitudinal members are each pivotally mounted along the lateral sides of the rectangular framework to adopt either a vertical position in retracted position of the trailer, where the longitudinal members and the panels abut one another; or, a horizontal position in expanded position of the trailer where the longitudinal members then constitute extension of the platform.
According to a preferred embodiment of the invention, each longitudinal member comprises a secondary panel perpendicularly fixed at one end of the longitudinal member thus constituting an extension of the front panel in expanded position of the trailer when the longitudinal member is in horizontal position; when the member is in vertical position, in the retracted position of the trailer, the secondary panel is positioned outside the front panel and against the latter, while each lateral panel rests on a corresponding longitudinal member, the latter then being in vertical position.
According to another preferred embodiment of the invention, the articulation device comprises a pivoting rod, that is articulated at one end along a leg of a frame and at the other end along a corresponding leg of the other frame, the pivoting rod being mounted on the framework, and enabling a 180xc2x0 rotation of the rod causing a drawing in or drawing out of the frames between in the retracted and expanded positions, by articulation of the rotary rod with respect to the two legs on which it is articulated.
Preferably, the articulation device comprises two articulated rods, so that each leg of a frame is connected to a corresponding leg of the other frame.
According to another preferred embodiment of the invention, the trailer comprises a pivot pulley fixed to each of the articulated rods, at a location where the latter pivots on the framework, driving means provided for rotation of the two pulleys and thus causing a 180xc2x0 rotation of each of the articulated rods, and consequently, drawing out or in of the two frames.
Each pivoting rod is preferably pivotally mounted on the central link of the framework.
According to another preferred embodiment of the invention, the trailer comprises a drawbar that is mounted on the framework, a transmission mounted on the drawbar, the transmission being operatively connected to each of the articulated rods, by means of the pivot pulleys.
Preferably, the trailer according to the invention comprises a support for each of the two legs of the two frames, the supports being shaped to define a rectangular opening capable of receiving one of the legs and permitting a transverse and longitudinal sliding of the legs in the supports.
According to another preferred embodiment of the invention, the transmission comprises a driving pulley as well as a crank in order to rotate the driving pulley. The pivot pulley and the driving pulley are preferably sheave wheels which are functionally connected to one another by means of a system of straps.